Continuous Transient Operation
In continuous operation, a repetitive pulse train switches between two load levels. Continuous transient operation is selected via the GPIB using the TRAN:MODE CONT command. For front panel operation, continuous transient
operation is automatically selected when transient operation is turned on( key).
The two load levels in the transient operation are the previously described main level (immediate or triggered) and transient level for current, resistance, or voltage. The rate at which the level changes is determined by the slew rate (see slew rate descriptions for CV, CR, or CV mode as applicable). In addition, the frequency and duty cycle of the continuous pulse train
are programmable. The frequency can be set from 0.25 to 10000 Hz at the front panel ( and ENTRY keys) or via the GPIB (TRAN:FREQ command) The duty cycle can be set from 3% to 97% (0.25 Hz to 1 kHz) or from 6% to 94%
(above 1 kHz) at the front panel( and ENTRY keys) or via the GPIB (TRAN:DCYC command).
For example, assume that the CC mode is active, the slew rate is at the default setting (maximum rate), and the applicable transient operation parameters have been set as follows:
HPSL Command | Description |
TRAN:MODE CONT | Sets continuous operation. |
CURR 5 | Sets main current level to 5 amps. |
CURR:TLEV 10 | Sets transient current level to 10 amps. |
TRAN:FREQ 1000 | Sets transient generator frequency to 1 kHz. |
TRAN:DCYC 40 | Sets transient generator duty cycle to 40%. |
TRAN ON | Turns on transient operation. |
Figure 2-5 shows the waveform that would result in this example. The module input current will slew to and remain at 10 amps for 40% of the period (400 μs), then slew to and remain at 5 amps for the remaining 60% (600 μs) of that cycle.
Figure 2-5. Continuous Transient Operation
The load module starts conduction at the main level (in this case 5 amps). When transient operation is turned on and at a time specified by the frequency setting the input level starts increasing at a rate determined by the slew rate. When the value specified by the transient level setting is reached, it stays there for the remainder of the time determined by the frequency and duty cycle settings. After this time has elapsed, the input level decreases to the main level again at the rate specified by the slew setting and stays there for the remainder of the period prescribed by the frequency setting.
Pulsed Transient Operation
Pulsed transient operation is similar to continuous operation with the following exceptions:
a.In order to get a pulse, an explicit trigger is required. The trigger can be an external trigger signal received via the TRIGGER input on the rear panel, the GPIB GET function, the *TRG common HPSL command, the TRIG subsystem HPSL command, or the ac line or internal timer signal.